SDL design is used to clarify and describe the client-to-server, server-to-client and server-to-server communication. A SDL design makes possible the wide use of simplifications and must not be seen as a real design but as a way to explain the principles of the invention.
A more detailed explanation of the terms and symbols used in the SDL design descriptions and examples are given in the accompanying FIG. 1.
The WWW and WAP are both technologies that give the user easy access to information and services via the Internet. In WWW and WAP the servers do not co-operate in a distributed manner. In fact they are not aware of each other. This means that the user has to know the specific address to the information/service he wants to get from the server. These addresses can be saved as bookmarks. In practice the user spends a lot of time to find the information and services he wants.
Companies that provide WWW and WAP portals have solved the problem to some extent. These portals works like an index or a table of content to information and services on the Internet.
There is a significant difference between the “fixed” Internet user and the mobile Internet user.
The mobile Internet user wants:                Services based on his current or other specified geographical location;        Fast access to services and information through a personalised interface;        The ability to filter information and choose services based on his personal requirements.        
The providers of information and services want:                To provide their information and services for users within a specific geographical area;        To provide their information and services in a way that makes them easy to access for the target group of users;        An easy technical way to keep their information and services updated.        
These requirements are not fulfilled with the technology available today. Servers need to be connected in order to provide specific location dependent services to a user that moves around.
“The Virtual Home Environment” (3G TS 22.121) is quite close to this idea with regards to the user profile and the functionality seen from the users perspective. However, it does not say anything about servers and network.
The latest improvement to the WWW portals is that the user can make his own portal based on a selected subset of the hyperlinks from the standard portal. This feature provides a user-friendlier interface than his bookmarks, which is really the same thing.
Different kinds of positioning technology are available or are being developed. There is work being done to provide the mobile Internet user with information and services based on his location. As far as the applicant knows, these are services which are not specified as part of a general network solution.
The current solutions for location dependent information and services are not part of a general solution that fulfils the requirements stated above.
The portals available today are static. The information level is quite high because they cover big geographical areas. This means that small information/service providers may not be allowed to “hook on” to these portals, or they can simply not afford it.
The location dependent services that are popping up today must be organised in a network to make them easy to access for the user.
With reference to the limitations of the prior art referenced above, it is an object of the invention to provide a flexible and affordable information system for providing location dependent information and services according to predefined needs of a mobile user and the needs of the information and service providers.
It is a further object of the present invention to alleviate the mobile user of location specific information and services of the tedious task of searching through the huge amounts of information and services available on the Internet in order to find information and services of interest.